From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.ciao.gmane.io!not-for-mail From: =?UTF-8?Q?Cl=c3=a9ment_Pit-Claudel?= Newsgroups: gmane.emacs.devel Subject: Re: Ligatures (was: Unify the Platforms: Cairo+FreeType+Harfbuzz Everywhere (except TTY)) Date: Sat, 23 May 2020 10:34:23 -0400 Message-ID: References: <20200517165953.000044d2@web.de> <83blmi7hys.fsf@gnu.org> <837dx55qff.fsf@gnu.org> <834ks95cmz.fsf@gnu.org> <4faa291f-f2df-36d1-73d5-332b93a9b6d8@gmail.com> <83wo544hx5.fsf@gnu.org> <831rnc43ih.fsf@gnu.org> <83ftbs2jr5.fsf@gnu.org> <838shk2ga3.fsf@gnu.org> <835zcn3iao.fsf@gnu.org> <83wo5321qp.fsf@gnu.org> <639a2445-3773-2455-92f6-38b3c5b5f7b5@gmail.com> <83mu5z171j.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="108651"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 Cc: alan@idiocy.org, pipcet@gmail.com, emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sat May 23 16:34:57 2020 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jcVEm-000S81-MR for ged-emacs-devel@m.gmane-mx.org; Sat, 23 May 2020 16:34:56 +0200 Original-Received: from localhost ([::1]:50038 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jcVEl-0005c6-Pv for ged-emacs-devel@m.gmane-mx.org; Sat, 23 May 2020 10:34:55 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:33452) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jcVEK-0005D4-Gf for emacs-devel@gnu.org; Sat, 23 May 2020 10:34:28 -0400 Original-Received: from mail-qt1-x82b.google.com ([2607:f8b0:4864:20::82b]:34508) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jcVEJ-0000jR-CK; Sat, 23 May 2020 10:34:28 -0400 Original-Received: by mail-qt1-x82b.google.com with SMTP id a23so10696803qto.1; Sat, 23 May 2020 07:34:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=mY1/5EEWFebYl3QM61ASOJBF352HB8V45LJPzz+EBTM=; b=pjGdOg4O4N1mOx2jnCkxGOTOQ0ZN5snx0/qZaaSm9l6Ag3FlSC/xzJTRz6ea2Vix3f ZizZT/YGXIxjNprrdIrcd/MtaVqzQLzF2qs0on3VNaeyrnuiVbivnkQ4wSKwL9+M+Om7 57cOhQbCs+ydpf5/msNaVYb2udU20yMqhvWjS84wt8EdJVUiBcFGghzI6Fgs5TNe24lK XCciGO6NShvrtr8iEObdXJgri2HZMn7J3m5cdy3Vird+a+xalpMun8lEWCGclOTkDVyD PaKxQhdDu7gGrglv+iK+y2uQHdXB7RUfyi69lTuFYUz79nMk2c3cj4zqDVe0KevvPxfV TnuA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=mY1/5EEWFebYl3QM61ASOJBF352HB8V45LJPzz+EBTM=; b=uldu1nvihaLEICyUTOx+8jQ1VImvxYgl1utDajJrpCBQGRnw8Yrj9GBzp93QmqoH1j xKLmhqYJ4a6+GC0IhwVxF6DKLDnLfp+qcaSPrWQP2mZc+xrHA1pdBgjf9oJLks5CVpUO dXj4r0W3WrCsVHuxY4nkXZGnF4a1Z3ssdeZKlBciQKP1AXfmpJtzqgCzN4v+sIdpU4Kn ralaG2VDmrV+clonXEkLHNY+F0Sr5mnOLTyK5yY3UVGrvRJmcwEpDG2BNPW48G1VN3sw lCSmwoI1BmQXdy1AWiGfaMMpctF3avUSDgiATr/Fx2y7Y/SA/Y6efj7kTr5L3QkqrUsk 0RNA== X-Gm-Message-State: AOAM531PGUxCjpQfjx2/+JeatUaagdtbqfRy9voE7x9DFCyPCbV0rCSs Ph/jEfmF7Lhv/QZAYMCUTm83UNro X-Google-Smtp-Source: ABdhPJx3e61R61+yvH+Zozg2aBhxIZWOSyny0b2Fpsblva9AjSo6GU5S37CoXFEMmSE6As/h2mj0nw== X-Received: by 2002:ac8:105:: with SMTP id e5mr21044574qtg.15.1590244465650; Sat, 23 May 2020 07:34:25 -0700 (PDT) Original-Received: from ?IPv6:2601:184:4180:66e7:bda5:ac5c:1de0:b677? ([2601:184:4180:66e7:bda5:ac5c:1de0:b677]) by smtp.googlemail.com with ESMTPSA id t88sm10662269qtd.5.2020.05.23.07.34.24 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 23 May 2020 07:34:25 -0700 (PDT) In-Reply-To: <83mu5z171j.fsf@gnu.org> Content-Language: en-GB Received-SPF: pass client-ip=2607:f8b0:4864:20::82b; envelope-from=cpitclaudel@gmail.com; helo=mail-qt1-x82b.google.com X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. X-Spam_score_int: -10 X-Spam_score: -1.1 X-Spam_bar: - X-Spam_report: (-1.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, FREEMAIL_REPLY=1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:251277 Archived-At: On 23/05/2020 02.47, Eli Zaretskii wrote: >> Cc: pipcet@gmail.com, alan@idiocy.org, emacs-devel@gnu.org >> From: Clément Pit-Claudel >> Date: Fri, 22 May 2020 16:02:22 -0400 >> >> What I don't understand is what it is about Emacs that means that we need special lists of regexps for each new font, while other editors don't need them. > > Emacs doesn't need a special list for each font. I already said that > several times. Please look at some examples of composition rules we > already have, for example the Arabic rules at the very end of > misc-lang.el. Do you see any fonts mentioned there? These rules work > with any font that supports Arabic. The only thing I'm talking about is symbol compositions in programming fonts, and for these, we *will* need a custom list for each font, right? >> Each font offers a different set of symbol ligatures: there is no common superset that covers all fonts, except the ".+" regexp that Pip posted earlier. > > I'm not yet sure this is indeed so. I didn't see any reference which > implies that any combination of 26 ASCII letters could become a > ligature. I think that's where I'm confused. I'm talking of ligatures like -> and =>, which do not involve the 26 ASCII letters. > This is a discussion that didn't yet happen. It is quite possible > that in practice the list of ligatures we want to support is not very > long. E.g., the list in > https://github.com/tonsky/FiraCode/wiki/Emacs-instructions is not > long, and I doubt manu additions to it will ever make sense for us. As I said, this list is incomplete and broken. > And finally, if a given font doesn't support some ligature, the > original characters will be displayed "normally", so nothing is lost, > and there's no need to tune the list of ligatures to each and every > font. I said that as well several times already. As long as you can produce a superset of all ligatures, yes. My claim is that this superset is ".+". Otherwise, how do you handle the fact that Fira Code handles arrows of arbitrary lengths? Or is that different from ligatures?